( )a postman usually sends letters___ A by bike B by plane C by car D by ferry 邮递员通常是（ ）送信的.当然是A了,骑单车
( )they are taking about __advertisement.A a B an C these D / advertisement是可数名词,只能从AB里选,而这个词第一个音标是无间音标,所以选B.
( )there is __water in the pool.A many B few C a few D a lot of 池子里有（ ）水,一般情况下是有不少水的,而水是不可数名词,所以选D.
( )the bank clerk sees many students when he __to work.A walk B walks C is walking D walked 这个我认为选B,表示习惯性的动作.
( )my parents work in different ___ A factory B factories C advertisement boards D trees 我的父母在不同的工厂做事,不只一个工厂,当然用复数了,选B,而C advertisement boards的意思是广告牌的意思.